jQuery.extend({
    createUploadIframe: function(id, uri)
	{
			//创建iframe
            var frameId = 'jUploadFrame' + id;
            var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
			if(window.ActiveXObject)
			{
                if(typeof uri== 'boolean'){
					iframeHtml += ' src="' + 'javascript:false' + '"';

                }
                else if(typeof uri== 'string'){
					iframeHtml += ' src="' + uri + '"';

                }	
			}
			iframeHtml += ' />';
			jQuery(iframeHtml).appendTo(document.body);

            return jQuery('#' + frameId).get(0);			
    },
    createUploadForm: function(id, fileElementId, data)
	{
		//创建表单域
		var formId = 'jUploadForm' + id;
		var fileId = 'jUploadFile' + id;
		var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');	
		if(data)
		{
			for(var i in data)
			{
				jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
			}			
		}		
		var oldElement = jQuery('#' + fileElementId);
		var newElement = jQuery(oldElement).clone();
		jQuery(oldElement).attr('id', fileId);
		jQuery(oldElement).before(newElement);
		jQuery(oldElement).appendTo(form);
		
		jQuery(form).css('position', 'absolute');
		jQuery(form).css('top', '-1200px');
		jQuery(form).css('left', '-1200px');
		jQuery(form).appendTo('body');		
		return form;
    },

    ajaxFileUpload: function(s) {
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = new Date().getTime()        
		var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data));
		var io = jQuery.createUploadIframe(id, s.secureuri);
		var frameId = 'jUploadFrame' + id;
		var formId = 'jUploadForm' + id;		
        if ( s.global && ! jQuery.active++ )
		{
			jQuery.event.trigger( "ajaxStart" );
		}            
        var requestDone = false;
        var xml = {}   
        if ( s.global )
            jQuery.event.trigger("ajaxSend", [xml, s]);
        var uploadCallback = function(isTimeout)
		{			
			var io = document.getElementById(frameId);
            try 
			{				
				if(io.contentWindow)
				{
					xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
					xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
				}
				else if(io.contentDocument)
				{
					xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
                	xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
				}						
            }
            catch(e)
			{
				jQuery.handleError(s, xml, null, e);
			}
            if (xml || isTimeout == "timeout") 
			{				
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    if ( status != "error" )
					{
                        var data = jQuery.uploadHttpData( xml, s.dataType );    
                        if ( s.success )
                            s.success( data, status );
    
                        if( s.global )
                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                    } 
                    else
                    {
                    	jQuery.handleError(s, xml, status);
                    }
                        
                } 
                catch(e) 
				{
                    status = "error";
                   	jQuery.handleError(s, xml, status, e);
                }

                if( s.global )
                    jQuery.event.trigger( "ajaxComplete", [xml, s] );

                if ( s.global && ! --jQuery.active )
                    jQuery.event.trigger( "ajaxStop" );

                if ( s.complete )
                    s.complete(xml, status);

                jQuery(io).unbind()

                setTimeout(function()
				{	
                	try 
					{
						jQuery(io).remove();
						jQuery(form).remove();	
						
					} catch(e) 
					{
						jQuery.handleError(s, xml, null, e);
					}									

				}, 100)

                xml = null

            }
        }
        
        if ( s.timeout > 0 ) 
		{
            setTimeout(function(){
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try 
		{

			var form = jQuery('#' + formId);
			jQuery(form).attr('action', s.url);
			jQuery(form).attr('method', 'POST');
			jQuery(form).attr('target', frameId);
            if(form.encoding)
			{
				jQuery(form).attr('encoding', 'multipart/form-data');      			
            }
            else
			{	
				jQuery(form).attr('enctype', 'multipart/form-data');			
            }			
            jQuery(form).submit();

        } catch(e) 
		{			
            jQuery.handleError(s, xml, null, e);
        }
		
		jQuery('#' + frameId).load(uploadCallback	);
        return {abort: function () {}};	

    },

    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        if ( type == "script" )
        {
        	jQuery.globalEval( data );
        }
            
        if ( type == "json" )
        {
        	//返回json字符串中含有pre标签信息，需替换掉
        	data = data.replace(/[<][\/]?(pre)[\s]*(style=\"word-wrap: break-word; white-space: pre-wrap;\")*[>]/gi,"");
			var dd=$(data+"<div></div>");
        	if(dd.lengh!=0){
        		data=data.replace(dd[0].outerHTML,"");
        	}
            eval( "data = " + data);
        }
        	
        if ( type == "html" )
        {
        	jQuery("<div>").html(data).evalScripts();
        }

        return data;
    },
    
    handleError: function( s, xhr, status, e ) {
        // If a local callback was specified, fire it
		if ( s.error ) {
			s.error.call( s.context || s, xhr, status, e);
		}
		
		// Fire the global callback
		if ( s.global ) {
			(s.context ? jQuery(s.context) : jQuery.event).trigger( "ajaxError", [xhr, s, e]);
		}
    }
})